A set of linearized equations describing the macroscopic motion of a plasma with anisotropic pressure, obtained originally by Grossmann, Hameiri and Weitzner, from the double adiabatic equations of Chew, Goldberger and Low, is solved numerically as an initial boundary value problem. Any three-dimensional anisotropic pressure equilibrium can be employed. The equilibrium is specified on a toroidal mesh in three dimensions so magnetic surfaces do not necessarily have to exist. The stability of the plasma in the stellarator experiments Proto-CLEO/CLEO, IMS, Wendelstein VII-A, and Heliotron-E is studied as a function of beta, defined in terms of energy density, and as a function of the ratio of parallel to perpendicular pressure, γ. In these devices, equilibrium and stability considerations both imply that the highest β may be obtained with p⊥ > p||.